Kim Philby in Russia in 1968, five years after defecting. Photograph: Daily Mail/Rex Features

Kim Philby, the most successful of the Cambridge spies, tried to drink himself to death in Moscow because he was disillusioned with communism and tortured by his own failings, his last wife has said in an interview.

Philby died in the city in 1988, 25 years after defecting to the Soviet Union, where he was employed as an occasional consultant to the KGB helping to prepare spies for missions to the west.

Rufina Pukhova, his Russian-Polish wife, said Philby struggled to control his drinking by downing only two glasses of cognac a night and then handing her the bottle to hide.

"His alcoholism was suicide," she told the Moskovsky Komsomolets newspaper. "He once even said that it was the easiest way to bring life to an end."

Pukhova, now 78, said she was irritated by stories about Philby's drink problem, but admitted he wasn't always able to stick to his two-glass rule. "If he continued drinking, he got inebriated quickly and changed in front of your eyes," she said. "But he never got aggressive, and just went to bed."

His habit was fuelled by his sorrow over what he saw around him, she added. "Kim believed in a just society and devoted his whole life to communism. And here he was struck by disappointment, brought to tears. He said, 'Why do old people live so badly here? After all, they won the war.'"

Born in India in 1912, Philby became a communist sympathiser after leaving Cambridge and began working as a KGB informer in the mid 1930s in London. He reported to the Soviet NKVD from the Spanish civil war under the guise of a correspondent for the Times, and in 1940 joined the Secret Intelligence Service (SIS, or MI6), becoming a double agent and passing many secrets to the Kremlin.

Philby's work led to the deaths of dozens of British agents, making him a reviled traitor once he was exposed in Britain. But in Russia he is still admired as a hero. A plaque in his honour was unveiled by the head of the foreign intelligence service at its headquarters in Moscow in December.

He and Pukhova married in 1971, when he was 59 and she was 38. Philby had defected to the Soviet Union from Beirut in 1963, and was treated with respect, but felt isolated. "Kim said to me, 'I came here totally fully of information, I wanted to give everything I had but no one was interested," explained Pukhova.

His drinking made him paranoid that his wife would abandon him.

"There was one funny incident," she remembered. "It was winter and we were going out for a walk and I found one of my boots had disappeared. It was a mystery. We searched every corner until Kim suddenly struck himself on the head with his hand, went to a cupboard and brought back the boot. He had got afraid that I would leave, and hidden the boot."

However, Pukhova said the fear that she would leave had helped her husband temper his intake in later years. "I tried everything to save him; after all, he was killing himself. He never promised to give up, but once, completely unexpectedly, he suddenly said, 'I'm afraid I'm going to lose you, I'm not going to drink any more.' It was a miracle. And he kept his word to the end." The two-drink tradition remained but in time there was no longer a need to hide the bottle, she added.

Philby had other less damaging routines: a cup of Russian tea at 7am and English tea with milk at 5pm, drunk from a fine porcelain cup.

Pukhova said he was a "special" and principled man. "Once, a big group of us were on a trip on the Volga: Kim and I and, of course, his KGB escort, and the escort's daughter. We got together in our cabin to discuss our plans.

"I said something to the escort and he just stayed silent, sitting, leafing through his magazine. Kim leapt up and shouted, 'Whoever is rude to my wife is rude to me!' You should have seen his face."

Cold war exiles

The gang of British spies who ended up in Moscow in the 1950s and 1960s were employed in KGB training schools and international research institutes. They met each other socially but soon fell out. Kim Philby drank while Guy Burgess, who was gay, missed his friends in London, including Anthony Blunt whose spying activities, though known to the government, were kept under wraps until they were exposed much later, in 1979. Donald Maclean, although arrogant and someone who liked a drink too, was regarded as more convivial. George Blake, who is still alive, got on well with him than with Philby. Maclean bequeathed Blake his library of books, including Trollope, Macaulay's History of England, Morley's Life of Gladstone, and the Macmillan and Eden memoirs.

In contrast to Blake, Philby and Burgess – and to a less extent Maclean – suffered from nostalgia for Britain. Philby's less attractive personal qualities were matched by a charm to which many of his MI6 colleagues succumbed. Some could never quite come to terms that he was a traitor.